ESC: Long-Distance Running Appears Safe for the Heart

Action Points

Explain to interested patients that a series of abstracts suggests that marathon-type running does not appear to induce long-term changes in the heart, even in older people.

Note that one researcher suggests that novice older runners should still undergo basic heart tests before training for marathons or ultramarathons.

Note that these studies were published as abstracts and/or presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

STOCKHOLM -- Men and women who participate in endurance competitive marathon events appear to develop some transient heart changes, but overall these activities do not seem to have long-term harm for the vast majority of individuals.

In a series of reports presented at the European Society of Cardiology meeting, doctors found:

Older runners -- those over age 50 -- developed some cardiac changes following running in Berlin marathons, but the changes in diastolic and right heart function did not exceed normal ranges.

There are ethnic and sexual differences in changes in heart muscle that should be recognized before athletes with enlarged hearts are disqualified from competition.

No significant cardiac changes occurred among participants who were engaged in a week-long overland and water endurance exercise program.

On the other hand, ultra-endurance running -- races of 50 to 100 miles -- resulted in elevation of troponin-1 which could be related to heart muscle damage; many of these runners also developed electrocardiographic changes.

On the whole, "It is wonderful to see that older adults can participate in these endurance events without experiencing long-term heart damage," said Ileana L. Pina, MD, professor of medicine, epidemiology, and biostatistics at Case Western Reserve University, in Cleveland.

"Even if these individuals exhibit higher-than-normal biomarkers, these rapidly return to normal," Pina, a spokesperson for the American Heart Association, told MedPage Today in Stockholm.

In one study, researchers led by Fabian Knebel, MD, a cardiologist at the Medical Clinic for Cardiology, Angiology, Pneumology at the University Medicine Berlin, studied cardiac parameters for 167 runners -- all 50 years or older -- who participated in the 2006 and 2007 Berlin Marathon races.

They were examined 10 days before the race, immediately after running 26 miles, 385 yards in the marathon, and two weeks after the race.

Knebel said that immediately after the race, the heart rate in these runner was elevated from baseline -- 88 beats per minute at the end of the marathon compared with 62 beats per minute before the race (P<0.001), and 57.95 of the runners showed increases in troponin values.

However, these changes proved transient, he said. "Two weeks after a marathon, the key parameters were all back to normal levels," Knebel said. "The concerns people have about marathon running causing sustained damage to the heart appear to be unfounded."

In another study, researchers determined that Caucasian and black women athletes appear to have differences in anatomy which manifests as a larger heart among the black women.

Sanjay Sharma, MD, professor of cardiology at Kings College, in London, established that about 3% of black women athletes have a left ventricular wall thickness greater than 11 mm -- a level not exceeded by elite white women athletes. In black elite women athletes, the left ventricular wall thickness can reach 13 mm -- a level that would be considered abnormal for white women athletes.

He suggested that if sports policymakers used data derived solely from white athletes regarding what constitutes healthy heart function, "it could unfairly discriminate against black athletes by leading to unnecessary investigation or even disqualification."

In commenting on Sharma's study, Pina noted, "We have known there are differences between the sexes in cardiology, but it also appears there are genetic differences that involve ethnicity as well."

A third study that examined subjects who completed a five to seven day prolonged exercise event -- an 800 kilometer cross-country running and boating test -- found that the athletes who participated experienced no health-related abnormalities.

Researcher C. Mikael Mattsson, PhD, at the Karolinska Institute, Stockholm, suggested that the lack of cardiac fatigue seen among the 15 athletes studied might have been due to the low intensity exercise of the cross-country trek. "This might point towards exercise intensity, not duration, as the primary source for cardiac fatigue," he said.

That might have been borne out among participants who completed either a 50-mile or a 100-mile road race, said John Somauroo, MD, professor of medicine at Countess of Chester Hospital, England.

Of the 25 runners who completed the arduous race -- beset by thunderstorms and driving rain -- troponin levels were elevated in 21 of the men, and many developed bizarre electrocardiogram changes, Sumauroo and colleagues found.

"This study suggests that running continuously over 50 to 100 miles may not be good for the heart," Somauroo said.

Aside from the long-distance studies, the lack of long-term damage to these athletes' hearts may point to the human genetic makeup. "In evolution we were selected out as hunter-gatherers where we would run and hunt miles from home to find enough food for the day," Stephen Gielen, MD, associate professor of medicine at the University of Leipzig, Germany, and a spokesman for the European Society of Cardiology, told MedPage Today.

"It is astonishing the enormous exercise that the human heart can endure," he said. He noted that the long-distance running may be typical of the human condition that was developed before mankind became civilized.

He did note that the long-distance running events that Somauroo reported may represent the "edge of harmful" events.

Gielen said that individuals who decide to take up endurance running and are over age 40 should undergo cardiovascular screening before hitting the road.

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